The present invention relates to bridge transporting and launching trailers. More specifically, this invention relates to a trailer which may be used for quickly establishing a bridge.
Bridge launchers of various constructions have heretofore been known in the art. Such bridge launchers have usually been designed to function in military support roles for tanks, armored personnel carriers, military trucks, and similar military vehicles. To this end, the bridge launcher is used to establish a temporary bridge across a river, gully, or anti-tank ditch. Once the bridge has been established across the river, gully, or ditch, tanks or other military vehicles may proceed across the bridge to the other side of the otherwise impassable barrier.
Usually the bridge can be removed by the same vehicle used for launching the bridge so that the bridge may be used at the next obstacle. Also, removing the bridge will prevent enemy forces from using it without requiring the destruction of the bridge.
Bridge launching vehicles commonly must be used in rough terrain and are often carried by endless track vehicles constructed with the same traction, power drive mechanisms, and chassis as commonly used on tanks. In addition to providing traction in rough terrain, the mounting of the bridge and associated launching mechanism on top of an armored body of a military track vehicle will additionally protect military personnel while launching and retrieving the bridge. Clearly it can be expected that heavy enemy fire will be concentrated upon any bridge launching vehicle used under battlefield conditions. Unfortunately, the armor which is necessary to provide protection for the military personnel who launch and retrieve the bridge, also causes the bridge launching vehicle to be extremely heavy and relatively bulky. Excessive weight and bulkiness increases the difficulties in transporting such bridge launching vehicles by ship or plane to the battlefield location. Additionally, the armor plating and endless track on such vehicles is relatively expensive as is the cost of transporting the vehicles.
Among other problems associated with the manufacture of bridge launchers are the limitations in the weight and/or length of the bridge which can be safely launched from the vehicle. Specifically, the launching of a bridge may place great moments on the vehicle which could cause tipping of the vehicle. In order to avoid tipping, anchors or similar devices are often used to resist tipping of the vehicle at the bridge launching end. Even with such anchors, the bridge weight and/or length will be restricted in accordance with the limit of compression of the anchor or anchors and the weight of the bridge launching vehicle itself. By use of an anchor or anchors, the weight of the vehicle may be used to counter the moment encountered when launching the bridge. Accordingly, the stability of the bridge launching vehicle will be enhanced by increasing its weight relative to that of the bridge itself. However, an increase in vehicle weight may hinder or complicate transportation of the bridge launching vehicle.
Another problem with prior art bridge launchers is the inability to adapt to structural modifications. Not only have prior art bridge launching vehicles been limited in terms of the maximum length and weight of the bridges which can be launched, but they have also often been limited to launching of a particular length and/or weight bridge. Any significant change of bridge weight and/or length has commonly required redesign of the launching vehicle.
Another disadvantage of numerous prior art bridge launching vehicles is their complexity in construction and associated high cost. In particular, it is desirable to have the bridge launching vehicle carry the bridge with the center of gravity of the bridge above or approximately above the center of gravity of the bridge launching vehicle. This maintains the bridge launching vehicle quite stable while the vehicle is being moved. However, when launching the bridge, relatively complex mechanisms have often been required to move the bridge to the front (or back) of the vehicle and to launch the bridge without putting too great a moment on the bridge launching vehicle.
Still another problem with prior art bridge launchers is that their relatively slowness in launching a bridge. For military operations this may present an intolerably long time during which the bridge and launcher is highly vulnerable to enemy fire.
Prior art methods of transporting bridge launching vehicles typically use a helicopter, the vehicle being attached by cables. Prior art bridge launchers generally are too cumbersome to allow their transportation by airplane without separation of the bridge from the launching vehicle and/or substantial disassembly of the vehicle.